Lifting-jack



(No Modem V2 Sheets-Sheet l. T. PHARES.

LIFTING JACK.

Patented Mar. 31, 1885.

@Afl/bow N, Pains. Plwnrumogmphcr, wagmgwn, n. c.

(No Mode1,) 2 Sheets-Sheet 2.

T. PHARES.

LIPTING JACK.

No; 314,716.` Patented Mar. s1, 1885.

N. PETERS Phmamhnguplm. wnhmgxm D. C,

Nrrnn @Tatras Fatemi tries..

THOMAS PHARES, OF EUREKA, CALIFORNIA.

LlFTlNG-JACK.

SPECIFICATION ormingpart of Letters Patent No. 31e-,716, dated March.31, 1885.

Application filed August 19,1854. (No m' del.)

.T all whom L'mctg/ concern/.f

Be it known that I, IHoMxs Pannes, of Eureka, Humboldt county, StateofCalifornia, have invented an Improved Lifting-J ack; and I herebydeclare the following to be a full, clear, and exact descriptionthereof.

My invention relates to certain improvements in that class of implementsknown as pawls are held out of contact with the bar, as i will be morefully described by reference to th accompanying drawings, in which-Figure lis avertical section ofthe standard,

' showing thepawl block or head with its pawls engaging with therack-bar, and the frictional clamp drawn back out of contact. a similarsection with the pawls disengaged and the frictional device in contactwith the rack-bar. Fig. 3 is an enlarged perspective view with `part ofthe side broken away. Fig. 4 is a fron-t view showing plate fordisengaging the pawls.

A is the standard of my jaclr,wliich may be formed of wood or iron, andis provided with a suitable base, as shown. This Istandard is slotted orformed with a deep channel from one side,and the rack-bar B is adaptedto move up and down within the channel,which serves as a guide for it.This rack-bar has a plate, O, at the top,upon which the articleto belifted will rest conveniently, and an anti-friction roller, D, at thelower end moves in contact with the rear of the channel and standard.Another roller, E, is fixed near the top ofthe standard, and fits into achamber or depression, F, in

the rear part of the rack-bar, so that the lat ter moves easily, and notmuch of the lifting power is lost by friction. The pawl block or headGis adapted to receive a lever at its back,

and has a pivot-pin, II, near the center of the side which fronts therack-bar, and the pawls I and .I are pivotcd or hinged one above and onebelow this axis, so that when the block is made to oscillate about itsaxis the pawls alternately act to push the rack-bar upward, one beingdrawn back for a new hold while the other is forcing the bar upward,thus givingit a nearly contin nous movement to raise the article whichrests upon the plate C. When it is desired to lower the plate C with itsload, the pawls I and J are disengaged from the rack-bar, and thefrietional clamping device is employed to lower the rack-bar steadily.This device consists of the plates or jaws K, which have their frontedges adapted to press against the sides of the rackbar. A block orhead, L, is perforated at the rear to receive the lover by which it isactuated, and this block hasatongue, M,whicli projects between the sideplates, K. Trunnions N, which project from each side of the tongue M,pass through holes in the plates K, so that their ends are flush withthe outside faces of the I plates. Fig.2shows A hole, O, is boredeccentrically through the trunnions, and a pin through this and thesides ofthe standard serves as an axis about which the head andtrunnionsareturned by the action of the lever. It will bel seen that when thishead stands in such a position that the pin or axis is nearest to therack-bar the holding-jaws K will be drawn back from the bar and will notpress upon it at all. When the lever is moved so as to turn theeccentric the jaws iirmly against the sides of the rack-V bar, and thusvhold it in any position by frictional contact, and this may be regulatedby a movement of the lever so as toV correspond with the load, and thuslower it steadily after the lifting-pawls have been disengaged.

In order to lift the pawls I and J ont of contact with the teeth of theraclebar, so as to permit the latter to be lowered when desired, Iemploy a sliding plate, I), which is fitted to slide up and down thefront of the rack-bar, between it and the rear portion of thepawlcarrying head G, as shown in Figs.` 3 and 4. This plate haselongated vertical slots at Q,

through which the pawls project so as to engage with the teeth of therack-bar, and the pawls are pressed forward by springs R, acting againsttheir backs, as shown in dotted 5 lines at Fig. 3. The lower end oftheplate P "is turned upward at S, and a blocl,T, is fixed so that thisturnedup 'end slides over it, and may either be drawn down below itslower end, so that the pawls will pass through slots Io Q and engagewith the rack, or it may be moved upward until the part S engages with anotch, (shown at U, Fig. 5,) when the lower ends ofthe slots Q willpress pawls backward until they are disengaged from the rack-bar,

y[5 so that it may be lowered at will.

V is a pawl hinged to the upper portion of the head G, so that its pointmay be raised to engage with a notch, XV, in the lower part of the headL when the weight has been raised 2o to a sufcient height, and if itisdesired again tolower the rack-bar B this pawl V is raised until itspoint engages notch NV, the head G being pressed downward. Vhen the headG is again lifted by its'lever, the pawl V will also push head L upward,thus rotating eccentric trunnions N, and causing plates K to pressagainst the sides of the rack-bar with sufficient friction to hold itand its load. The sliding plate Pis then moved upward un- 3o til it hasdisengaged the pawls I and J from the rack-bar, which is thus leftsupported by the frictional pressure of the plates K. By depressing thelever in the head G this pressure will be relieved to such an extent asto allow the rack-bar to slide down at any desired rateof speed, thuslowering theload again. Having thus described my invention, what I claimas new, and desire to secure by Letters Patent., is-

l. The friction-clarnp consisting of thejaws 4o K. the head L. with itsoperating-lever, and the trunnions N, turning in holes in the plates orjaws K, andy having ajournal pin or axis eccentric to the circumference,whereby the jaws are forced against the rack-bar by the movenient of thelever, substantially as herein described. Y

2. In a lifting-jack, the standard A, vertica1ly-moving rack-bar B, thepawl-block G, with its lever and pawls I and .I,with the plate 5o P, incombination with the friction-clamp K, L, and N, substantially as andfor the purpose herein described. I

3. In a lifting-jack, the oscillating pawlblock with the vpawls I and Jengaging the rack-hama frictioirclamp, K, with its eccentricoperatinghead L, having a recess or notch at its iowerside, togetherwithan arm or pawl,

V, hinged to the upper part of the block G, so that it may be niade toengage with therecess 50 in the head L, substantially as and for thepurpose herein described.

Y 4. In a lifting-jack. the standard with avertically-sliding raclebar,an oscillating head having pawls I and J engaging the rack-bar, togetherwith the sliding plate P, having slots through which the pawls project,and by which they may be thrown out ot' contact with the rack-bar,substantially as herein described.

In witness whereof I have hereunto set my hand. v

THOMAS PHARES.

YWitnesses:

DAVID WrLsoN, CHARLEs H. HENRY.

